// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/unguessable_token.h"

#include "base/format_macros.h"
#include "base/rand_util.h"
#include "base/strings/stringprintf.h"

namespace base {

UnguessableToken::UnguessableToken(uint64_t high, uint64_t low)
    : high_(high)
    , low_(low)
{
}

std::string UnguessableToken::ToString() const
{
    return base::StringPrintf("(%08" PRIX64 "%08" PRIX64 ")", high_, low_);
}

// static
UnguessableToken UnguessableToken::Create()
{
    UnguessableToken token;
    // Use base::RandBytes instead of crypto::RandBytes, because crypto calls the
    // base version directly, and to prevent the dependency from base/ to crypto/.
    base::RandBytes(&token, sizeof(token));
    return token;
}

// static
UnguessableToken UnguessableToken::Deserialize(uint64_t high, uint64_t low)
{
    // Receiving a zeroed out UnguessableToken from another process means that it
    // was never initialized via Create(). Treat this case as a security issue.
    DCHECK(!(high == 0 && low == 0));
    return UnguessableToken(high, low);
}

std::ostream& operator<<(std::ostream& out, const UnguessableToken& token)
{
    return out << token.ToString();
}

} // namespace base
